Safety-plug.



E. H. BASTION.

SAFETY PLUG.

APPLICATION FILED JULY 3, 1909.

950,271. I Patented Feb.22, 1910.

WITNESSES IIVVENT OR Elisha Hfias [1107a By M g 6' ATTORNEYS ELISI-IA I-I. BASTION, OF FAIRIBURY, ILLINOIS.

SAFETY-PLUG.

To all whom 'it may concern:

Be it known that I, ELISHA H. BASTION, a citizen of the United States, and a resident of F airbury, in the county of Livingston and State of Illinois, have invented a new and Improved Safety-Plug, of which the following is a full, clear, and exact description.

The invention relates to steam boilers, and its object is to provide a new and improved safety plug, for convenient attachment to the crown sheet, fire sheet or other part of a boiler, to indicate danger in case of a low water level, and arranged to prevent the fusible material from being dislodged or blown out of the plug body by pressure in the boiler, to insure an even heating of the fusible metal core, to prevent the plug body from being clogged up by sediment, and to provide a ready flow of the molten metal out of the body of the plug and to permit the free escape of the pressure to relieve the boiler of undue strain. For the purpose mentioned the body of the plug is provided with a chamber, closed at one end and open at the other end, the chamber having ports in the side wall, and a core of fusible material normally filling the said chamber.

A practical embodiment of the invention is represented in the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure l is a side elevation of the fusible plug, as applied to a boiler, shown in section; Fig. 2 is an end elevation of the plug; Fig. 8 is a longitudinal central section of the plug on the line 33 of Fig. 2; and Fig. 4. is a cross section of the same on the line 4-4 of Fig. 3.

The metal body A of the safety plug is provided with a threaded portion B, screwing in the crown sheet, fire sheet or other part C of the boiler, as indicated in Figs. 1 and 3, the threaded portion terminating in a head D of polygonal shape, for conveniently screwing the plug in place by the use of a wrench or other tool. The body A of the plug is provided with a chamber E, preferably made conical, and closed at its base end and open at its apex or small end at the face of the head D, and the side Specification of Letters Patent.

Application filed July 3, 1909.

Serial No. 505,841.

wall of the chamber E is provided with ports F, preferably three in number, as indicated in Fig. 4, and spaced equidistant apart, so thatthe ports are not located diametrlcally opposite one another. The chamber E is filled with a core G, of a fusible material, such as is usually employed in safety plugs of this type. Now when the safety plug is in use, it is evident that the pressure on the apex end of the core G is not liable to d slodge the core in the body A, as the opposite end is closed and forms aseat for the base end of the core. As the core Gr cannot be dislodged it does not form an opening or a recess liable to fill with sediment, which when it becomes hardened closes the chamber at both ends, to prevent escape of pressure, even if the core G should melt and run out of the chamber E by way of the ports F. The aggregate area of the ports F approXi mately corresponds to or equals the area of the outer or apex end of the chamber E, so that when the core G has melted and has run out of the chamber E then a free escape of the boiler pressure is had by way of the ports F and the open end of the chamber E.

The safety plug shown and described is simple and durable in construction, can be cheaply manufactured and readily screwed in position on the proper part of the boiler.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

A safety plug for boilers comprising a body having a chamber closed at the inner end of the plug, and having an outlet at the outer end, said chamber gradually decreasing in cross section from the closed end to the outlet, of said plug body having radial openings communicating with the chamber for the purpose specified, and a core of fusible material filling the chamber and the openings.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ELISHA H. BASTION.

Witnesses:

J. F. MCDOWELL, G110. B. GORDON.

Patented Feb. 22, 1910. 

